During hot summer days, a refreshing cool drink quenches thirst and could even help one improve one's work efficiency. However, any cool drink will inevitably absorb heat from the environment, making the cool drink warm. One must either finish the drink in a hurry and thus unable to fully enjoy the moment, or cool the drink down again using a refrigeration device, an unsatisfactory solution which takes time to complete. A simple solution is to add ice cubes into the drink directly. Although the ice cubes can cool the drink quickly, the melting ice cubes will also dilute the drink and make it lose its original taste. Moreover, when taking the drink to travel from one place to another, the cool drink can only last for a short time even if the drink is contained in an insulated vessel.
Conversely, heating food like steak can be done using the common stove or heated igneous rocks. The steak is put on a flat igneous rock and served directly, thus allowing the one could decide for himself/herself the degree of cooking needed based on one's personal preference. As the rock must have high thermal resistance and thermal capacity, from the preference is to use lava rocks from volcanoes. This introduces two problems: first is the need to process any lava rocks into surfaces suitable for serving foods, and the second is the wear and tear of the processed rock surface from repeated use. The challenge is to make use of technology to replace the heavy and rare stones to lower cost.
Many people like spreading a layer of butter on a piece of bread such as a toast or croissant for breakfast or dessert. Although seemingly simple to do, it is not always easy to spread butter because butter is usually kept in a cold state in a refrigerator. Using table knife or other kitchen utensil to carve butter entails large amount of force. Consequently, some people heat the table knife or utensils in hot water in an attempt to use stored heat to help melt the cold butter, thus enabling a smooth carving and spreading motion.
However, the above methods require extra effort and preparation. When spreading butter on bread, one may not have access to hot water. Having hot water near dining surfaces may result in spilling water. In addition, the utensils in question are usually small in size with limited heat storage capacity, making repeated spreading action over multiple breads impractical. If the utensil is overheated in any way to store more heat, the overheated utensil handle may cause injury to one's extremities. Also, if the utensil is overheated, the butter may become over melted thus defeating the purpose.
Some practitioners propose filling the handle of certain utensils with mercury. One holds onto a metallic handle to first transmit heat into the mercury, then through the conduction and convection of mercury during the rigorous shaking, the temperature in the front end of the utensil will increase to facilitate the cutting action. However, as this type of tool has a low thermal capacity, the user must hold and repeatedly shake the tool in order for it to work. Not only is mercury expensive, it is also highly poisonous. Any accidental leak, even minute amounts onto foods will lead to mercury poisoning.
One faces similar challenge when scooping frozen ice cream. Some practitioners propose electrically charging the ice cream scoop, but this method is inconvenient. Electric ice cream scoop melts the ice cream, resulting in soupy texture that is not desired. Electrical cords or batteries from batteries are cumbersome as well.
To sum up, insulated food and beverage containers, bottles, cups, and jars in the market today such as the Thermos, use insulation to reduce heat transfer between the inner and outer shells of the same vessel, so as to extend the current temperature of the foods and slow down the thermal balancing with the ambient environment. However, it doesn't solve the problem essentially as it can't heat or cool the food. Another way is electric heating. For example, a cooling chip is added to create a bi-directional temperature difference for heating/cooling by using the current input. However, the temperature difference provided is quite limited for smooth food processing. On the other hand, food processing will rely on power supply, lacking the convenience of portability.
The present invention proposes a thermal exchange food processing device accommodating phase change material and method of producing the same. By using the high latent heat feature of the phase change material, it could absorb/release large amounts of latent heat during the phase change process, so as to provide the thermal exchange for food processing. Take common salty water as an example. When the salt content reaches saturated status, its melting point could be reduced to −21° C. When the ice in solid phase is transformed into water, the melting latent heat is 333 kJ/kg, and the heat required is enough to cool the water in an equivalent mass of 80 to 0. It also indicates that when the ice made from salty water is melted from solid to liquid phase, it could absorb and store large amounts of heat for cooling the foodstuff.
On the contrary, let us take paraffin (melting point at 60° C.) as an example, whose specific heat is about 2.5 kJ/kg for each degree within the ambient range. The solidification of liquid phase requires latent heat of about 220 kJ/kg. That is, a kilogram of paraffin heated to 150° C. could heat 10 ounces of steak (about 284 g) from ambient to more than 60° C. and keep the temperature for some time by cooling it to 60° C. and solidifying it. If the invention could make good use of the latent heat of the material, it could be applied not only to process taken-out food, cool and frozen drinks in real time, but also to process hot food items like steak. It could be a convenient processing device on one hand and could increase the cooking enjoyment on the other.
This case proposes a thermal exchange food processing device and method of producing the same, expecting to effectively achieve the heating/cooling purpose without power supply. In this way, it will not only avoid the increase of manufacturing cost brought about by a complex structure, but also keep the compact shape. Moreover, it decreases the temperature restriction and allows people to enjoy food in broader environment conditions, so as to bring more fun and increase life quality.